1. Field of the Invention
The present invention relates generally to a magnetic tape library apparatus. More particularly, the invention relates to a picker mechanism to perform movement of a magnetic tape cartridge.
2. Description of the Related Art
Conventionally, in a magnetic tape library apparatus, various picker mechanisms have been proposed for taking out a magnetic tape cartridge from a magazine storing a plurality of magnetic tape cartridges and transporting the magnetic tape cartridge to a magnetic tape drive reading and writing a magnetic tape housed within the magnetic tape cartridge.
One example of the picker mechanism has been disclosed in Japanese Unexamined Patent Publication No. 11-167757. In the above-identified publication, in order to change direction by pivoting the picker, a motor installed within a shaft located at the lower portion of the picker is used. An internal gear is rotated by an external gear connected to the motor. The picker is mounted on the rotating internal gear to perform changing of direction.
On the other hand, another example has been disclosed in Japanese Unexamined Patent Publication No. 2000-48451. In the above-identified publication, a hand mechanism is driven in back and forth direction by means of a pulley and a belt. On the other hand, in an ejecting operation of the magnetic tape cartridge within the picker by the hand mechanism, a hand is opened when the hand mechanism is moved to at the up-front position of the picker, and operation is ended in the condition where the hand is opened.
However, when the motor installed within the shaft located lower portion of the picker is used in order to perform changing of direction by pivoting the conventional picker, size of the picker in the vertical direction becomes large by installing the motor at the lower portion of a picker body. Therefore, large stroke for vertical movement of the picker within the magnetic tape library apparatus cannot be certainly obtained to restrict storage position of the magnetic tape cartridges to make number of tapes to be stored.
On the other hand, when the pulley and the belt is used for driving the hand mechanism in back and forth direction, it becomes necessary to expand the overall length of the picker for the length corresponding to a diameter of the pulleys located at opposite ends of the belt in order to certainly obtain back and forth stroke of the hand mechanism. On the other hand, at the end of the magnetic tape cartridge ejecting operation of the picker, the hand mechanism is located at the front side of the picker in the condition where the hand is held open, occupying area of the picker becomes large to require certainly provide large space for changing direction of the picker within a casing of the magnetic tale library apparatus. For this reason, down-sizing of the magnetic tape library apparatus becomes difficult.